The present invention relates to wet wipers and, more particularly, to a wet wiper product having a liquid preservation system of citric acid and sorbic acid.
Wet wiper products require preservative properties to destroy or inhibit the growth of various microorganisms, bacteria, yeast, and molds. The use of a chemical preservative agent dispersed or dissolved in a liquid phase of a wet wiper has previously met various disadvantages because the nature of the required chemicals and the complexity of the final liquid phase formulations typically result in harsh or irritating residues being left behind on the skin of the user.
The preservative used in a wet wiper should meet two often competing criteria, namely effectiveness as a preservative and non-irritability in contact with human skin. As resistant strains to commonly utilized preservatives appear, the industry has typically increased usage levels and the number of preservative components in the wet wiper. As more potent strains of preservatives are utilized to achieve the desired effect, skin irritations and allergic reactions are often provoked in the user.
In an attempt to solve these problems, U.S. Pat. No. 4,615,937 to Michael P. Bouchette discloses that a superior wet wiper product can be produced in which the antimicrobial treatment is substantive to the wet wiper fibers. As a result of having the antimicrobial agent substantive to the fibers, no chemicals in the liquid or lotion phase of the wiper are required. Hence, no harmful residue is left on the skin of the user.
As a further improvement, U.S. patent application Ser. No. 854,811, filed on April 23, 1986 by Michael P. Bouchette et al., entitled "An Antimicrobially Active Wet Wiper" discloses a wet wiper that has both a substantive antimicrobial agent, such as an organo-silicon quaternary ammonium salt, on the fibers of the wet wiper product and a second antimicrobial agent, such as an organic acid, in the liquid or lotion phase of the wiper. This application notes that the combined use of the substantive antimicrobial agent and the antimicrobial agent in the liquid or lotion phase enhances the antimicrobial effects of the wet wiper.
These wet wipers, nevertheless, still require an antimicrobial agent substantive to the fibers of the wiper. It would be advantageous to develop a wet wiper that dispenses with the need of having such a substantive antimicrobial agent, but that does not leave a harsh or irritating residue on the user's skin.